• Title/Summary/Keyword: Spatial Boundary

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Characteristics of Static Buckling Load of the Hexagonal Spatial Truss Models using Timber (목재를 이용한 육각형 공간 트러스 모델의 정적좌굴하중 특성)

  • Ha, Hyeonju;Shon, Sudeok;Lee, Seungjae
    • Journal of Korean Association for Spatial Structures
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    • v.22 no.3
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    • pp.25-32
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    • 2022
  • In this paper, the instability of the domed spatial truss structure using wood and the characteristics of the buckling critical load were studied. Hexagonal space truss was adopted as the model to be analyzed, and two boundary conditions were considered. In the first case, the deformation of the inclined member is only considered, and in the second case, the deformation of the horizontal member is also considered. The materials of the model adopted in this paper are steel and timbers, and the considered timbers are spruce, pine, and larch. Here, the inelastic properties of the material are not considered. The instability of the target structure was observed through non-linear incremental analysis, and the buckling critical load was calculated through the singularities and eigenvalues of the tangential stiffness matrix at each incremental step. From the analysis results, in the example of the boundary condition considering only the inclined member, the critical buckling load was lower when using timber than when using steel, and the critical buckling load was determined according to the modulus of elasticity of timber. In the case of boundary conditions considering the effect of the horizontal member, using a mixture of steel and timber case had a lower buckling critical load than the steel case. But, the result showed that it was more effective in structural stability than only timber was used.

A Study on Range of Environmental Impact Assessment for Cumulative Effect Assessement - A Review on Living Environment Sector - (누적영향평가를 위한 평가범위 산정에 대한 연구 - 생활환경분야를 중심으로 -)

  • Kim, Youngha;Lee, Onkil;Lee, Youngsoo
    • Journal of Environmental Impact Assessment
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    • v.17 no.5
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    • pp.299-309
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    • 2008
  • Cumulative effects can be defined as impacts on environment which results from incremental impacts of a proposed project, which covers other past, present, and reasonably foreseeable future actions. The necessity of Cumulative Effect Assessment is that, when there are several projects near the project area, environmental effects of individual project can be larger or smaller than those of individual project without having projects nearby because of synergy, ascending and descending effects. This study was intended to help Environmental Impact Assessment practitioners identify spatial and temporal boundaries during the scoping stage. To do this, literature review of domestic and foreign legislations, guidelines, textbooks and papers related to Environmental Impact Assessment and Cumulative Effect Assessment was accomplished. This study suggests that continuous research be needed in order to identify spatial boundaries for other assessment fields and to develop methodologies for cumulative effect assessment.

A GEOMETRIC CRITERION FOR THE WEAKER PRINCIPLE OF SPATIAL AVERAGING

  • Kwean, Hyuk-Jin
    • Communications of the Korean Mathematical Society
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    • v.14 no.2
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    • pp.337-352
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    • 1999
  • In this paper we find a geometric condition for the weaker principle of spatial averaging (PSA) for a class of polyhedral domains. Let \ulcorner be a polyhedron in R\ulcorner, n$\leq$3. If all dihedral angles of \ulcorner are submultiples of $\pi$, then there exists a parallelopiped \ulcorner generated by n linearily independent vectors {\ulcorner}\ulcorner in R\ulcorner containing \ulcorner so that solutions of $\Delta$u+λu=0 in \ulcorner with either the boundary condition u=0 or ∂u/∂n=0 are expressed by linear combinations of those of $\Delta$u+λn=0 in \ulcorner with periodic boundary condition. Moreover, if {\ulcorner}\ulcorner satisfies rational condition, we guarantee the weaker PSA for the domain \ulcorner.

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A Study on the Spatial Characteristics of Alvaro Siza's Education Facilities - Focused on the Planning of Learning & Transitional Space - (알바로.시저의 교육시설에 나타나는 공간적 특성에 관한 연구 - 학습공간 및 전이공간을 중심으로 -)

  • Kim, Jin-Mo
    • Journal of the Korean Institute of Educational Facilities
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    • v.16 no.1
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    • pp.79-86
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    • 2009
  • The purpose of this study is to suggest the design guidance of education facilities by analysing Alvaro Siza's education facilities of which considered having idiosyncratic spatial characteristics. Focusing on the his planning of learning and transitional space of education facilities, this study aims at eliciting the spatial characteristics of his architecture. In doing so, this study tries to figure out his basic method of reification of his basic architectural concept which is articulated in learning space and transitional space of education facilities by introducing the boundary element and penetration of light in order to support student's learning activity and foster abundant cognitive experiences. Therefore, this study presents the feasible supplementary design method for future education facilities to be appropriate not just for quantitative factors, but for qualititative aspects such as user's psychological fulfillment, and emotional satisfaction.

The effect of error sources on the results of one-way nested ocean regional circulation model

  • Sy, Pham-Van;Hwang, Jin Hwan;Nguyen, Thi Hoang Thao;Kim, Bo-ram
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.253-253
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    • 2015
  • This research evaluated the effect of two main sources on the results of the ocean regional circulation model (ORCMs) during downscaling and nesting the results from the coarse data. The two sources should be the domain size, and temporal and spatial resolution different between driving and driven data. The Big-Brother Experiment is applied to examine the impact of them on the results of the ORCMs separately. Within resolution of 3km grid point ORCMs applying in the Big-Brother Experiment framework, it showed that the simulation results of the ORCMs depend on the domain size and specially the spatial and temporal resolution of lateral boundary conditions (LBCs). The domain size can be selected at 9.5 times larger than the interest area, and the spatial resolution between driving data and driven model can be up to 3 of ratio resolution and updating frequency of the LBCs can be up to every 6 hours per day.

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The Study on the Improvement of Principle in Determining Road Boundary Used by Geographical Features (지형지물을 이용한 도로경계 설정 원칙의 개선 방안)

  • Jeon, Yeong-Gil
    • Journal of Cadastre & Land InformatiX
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    • v.46 no.2
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    • pp.93-105
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    • 2016
  • Among 28 land Categories, 'road' is that most frequently established or transformed. Like that of other 27 land categories, the boundary of road should be defined by boundary making principles and then fixed by cadastral laws. But, some criteria to determine the land boundary, especially in boundary making rule which can be used by geographical features, is confused partly in Land Use Planning stages. Because the purpose of making any rules in fixing road boundary may be misinterpreted, the gap between law and real land boundary can be occurred. Those related rules in determining the land boundary must be improved urgently. Cut surface' or 'slope' should be conformed as a legal term and I suggest that 'Structures' must be changed to 'geographical features'.

편미분방정식 해의 공간적 감소율을 결정하는 푸앵카레 상수

  • 송종철
    • Journal for History of Mathematics
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    • v.13 no.2
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    • pp.87-94
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    • 2000
  • This paper investigates history and modern developments concerning spatial decay estimates for solutions in a semi-infinite cylinder or strip, in which model equations are defined with appropriate homogeneous lateral boundary conditions and initial conditions but left end boundary data are assumed. Our aim is to show this Saint-Venant type decay rate dependent critically on the Poincare constant resulting from characterizing variational principles.

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A Fundamental Study on the Maintenance of Administrative Boundaries based on Spatial Information (공간정보기반의 행정경계 정비를 위한 기초연구)

  • Yun, Ji-Ye;Park, Hong-Gi;Choi, Yun-Soo;Nam, Dae-Hyun
    • Spatial Information Research
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    • v.20 no.1
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    • pp.47-57
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    • 2012
  • An Administrative Boundary is the basic of spatial information to cover geographical and regional area. Its importance has arisen in our society at the Smart world era. However, it is difficult to serve exact boundary's lines as administrative boundaries are based on the cadastre lines of land register ; these partly are overlay each other or has gaps. So, it Should be adjusted. But, the maintenance work of administration boundaries causes a conflict or confusion unless we offer concrete procedures and detailed plans previously. Therefore, a rational method is required to prevent side-effects such as confusion, disagreem ent and a conflict etc. In this Study, we present a method and 5 step procedures to make better use in a practical maintenance work. we researched on basic studies of Administrative boundary's concept, history. And we performed a field survey as well as analysis of current problems. considering these results, we suggest usage of various spatial data sources, stake-holders' participation, a method of Nearest district's boundaries to maintain administrative boundaries. Throughout the method, we expect it to serve correct boundary-data to various fields without a big confusion. it is also useful to apply its results not only for re-surveying our land but for recording appropriate boundary-data as rational lines.

A Study on the Optimum Thickness Distributions of Plate Structures with Different Essential Boundary Conditions (경계조건에 따른 판 구조물의 최적두께분포에 대한 연구)

  • Lee, Sang-Jin;Kim, Ha-Ryong
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.4 s.18
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    • pp.53-59
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    • 2005
  • This paper provides the results of the investigation on the optimum thickness distribution of plate structures with different essential boundary conditions. In this study, the strain energy to be minimized is considered as the objective function and the initial volume of structures is used as the constraint function. The computer-aided geometric design (CAGD) such as Coon's patch representation is used to represent the thickness distribution of plates. A reliable degenerated shell finite element is adopted to calculate the accurate strain energy level of the plates. Robust optimization algorithms provided in the optimizer DOT are adopted to search the optimum thickness values during the optimization iteration. Finally, the square plate is used to find out the optimum thickness distribution of plates according to different essential boundary condition.

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An Efficient Contact Detection Algorithm for Contact Problems with the Boundary Element Method (경계요소법을 이용한 접촉해석의 효율적인 접촉면 검출기법)

  • Kim, Moon-Kyum;Yun, Ik-Jung
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.5
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    • pp.439-444
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    • 2009
  • This paper presents an efficient contact detection algorithm for the plane elastostatic contact problem of the boundary element method(BEM). The data structures of the boundary element method are dissected to develop an efficient contact detection algorithm. This algorithm is consists of three parts as global searching, local searching and contact relation setting to reflect the corner node problem. Contact master and slave type elements are used in global searching step and quad-tree is selected as the spatial decomposition method in local searching step. To set up contact relation equations, global contact searching is conducted at node level and local searching is performed at element level. To verify the efficiency of the proposed contact detection algorithm of BEM, numerical example is presented.